It has been estimated that regular use of inhaled corticosteroids (ICS) could reduce asthma-related hospitalization by 80%. Inhaled corticosteroids can significantly improve lung function, as well as prevent asthma exacerbations and death. Yet, ICS use remains low among patients with asthma, and studies measuring ICS adherence suggest that patients take their prescribed dose on only 20% to 73% of days. Together these findings suggest that increase adherence to ICS could result in significant improvements in asthma-related outcomes. Unfortunately, few behavioral or educational interventions have been shown to be very effective at improving adherence and asthma control, despite in some cases considerable time invested with the patient. Given the importance of adherence information to clinical decision making and disease management, it is surprising that not until recently have there been studies looking at the effects of providing this information to physicians. However, even the limited evidence from these small studies suggests that simply providing adherence information to clinicians can have a profound influence on patient adherence. One challenge is how to provide adherence information in the clinic setting where time and resources are often limited. Weighing canisters and electronic recording devices have been used to measure adherence to ICS, but these methods are too time consuming and expensive to be used by most clinicians. Medication adherence can also be estimated using pharmacy claims data. Since claims data are collected for other reasons, these pharmacy-based adherence measures are relatively inexpensive to generate and they are available on a large number of patients. This application seeks to develop and test a tool, which feeds back adherence information to physicians via the electronic medical record. These adherence measures will be generated by linking prescription data to pharmacy claims. This method has the potential benefit of being both easily use in clinical practice and financially sustainable. After a baseline period, primary care physicians will be randomized to receive ICS adherence information on their patients with persistent asthma. The primary outcomes will be the change in adherence from baseline and the difference in adherence between treatment groups. Also assessed will be changes from baseline and differences between the treatment and control groups in patient-clinician communication, patient attitudes toward adherence, outcomes related to disease control, and medical care costs.